In recent years, purchase of goods through the Internet is possible and bank transactions is possible without going to the bank. As the people, who purchase goods or do bank transactions using smart phones or personal computers (PCs), have been increasingly increased, there is a need for security for important information (for example, password and the like).
In response to operations requiring security being performed according to the needs, the operations may be performed in a secure mode. However, even in response to the operations requiring security being performed in the secure mode, the operations are performed in the insides of the devices and thus the user may not accurately know whether or not the devices operate in the secure mode while the user inputs the important information. To solve the problem, a secure indicator indicating that the electronic device operates in the secure mode is displayed. For example, in response to a bank application being executed through a smart phone, an icon indicating that the secure program is executing is simultaneously displayed in the upper left end of a display screen. In response to the secure indicator being displayed, the user knows that the electronic device operates in the secure mode and inputs the important information with an easy mind.
However, in response to a forged or leaked secure indicator being displayed, the user who cannot know that the indicated secure indicator is a forged or leaked secure indicator may think that the display device operates in the secure mode and input the important information and thus the secure problems may occurs.
Accordingly, there is a need for warning the user of a forged secure indicator in response to the forged secure indicator being displayed.